In the state of the art, bioreactors are commonly known as multi-use or as disposable (single use) systems. Multi-use systems consist of glass and steel and are adapted to be operated together with a control unit. These multi-use systems comprise a glass container and a cap closing the same. By way of this cap, for instance a stirrer, sensors, supply lines and the like are connectible to the interior of the container. As a disadvantage with respect to these multi-use systems, it has been experienced that after the termination of an application, the cleaning of the multi-use systems is sumptuous, time-demanding and, as a consequence, expensive. Additionally, a cleaning method to be used has to be validated first generating further costs. This is an essential fact of all bioreactor applications used on the industrial scale, for example for producing recombinant proteins.
Compared with the multi-use systems for cell culture processes described above, disposable systems are also known. These disposable systems or reactors, respectively, have normally the form of a bag. Such systems are described in EP 1 602 715 B1 and U.S. Pat. No. 6,432,698 B1. During their use, such bags are placed on a swivel table (rocker) and moved back and forth with the same. Compared to the multi-use systems in the stirred tank design described above, these bag reactors produce a smaller cell density than the multi-use reactors described above. In addition, such disposable reactors, which consist of multilayer bags, have the disadvantage that they are not recyclable due to the different plastic materials. For the applicant, these bag-reactors particularly have the disadvantage that conditions of cell culture processes known from glass and steel containers are not directly transferable to bag-reactors. Thus, the applicant has to optimize these bag-reactors for its respective application.
Stirred tank bioreactors are also known as disposable systems. For instance, they comprise a container, stabilised by an inflatable structure according to DE 10 2006 022 651. In US 2005/0239198 and US 2005/0239199, bags placed in a solid casing are used to receive the medium. This casing-bag combination comprises a stirring unit and is composed of disposable objects. The bags are not arbitrarily variable in their sizes since they have to be used in combination with a casing adapted in its size. Further, the flexible bags have a rigid integral adapter for a stirring unit. This construction is complex and expensive to manufacture.
The Superspinner D1000 of Satorius (DF001LS SSB-V) is an alternative construction. This bioreactor is qualified by its rigid walls and its removable cap. The latter has the risk that the bioreactor is opened and contaminated before application or it is opened during use and the contained material is contaminated. Thus, it is not clear for the user whether an actually not opened sterile bioreactor is provided.
It is the objective of the present invention to provide a disposable bioreactor which overcomes the disadvantages described above, has a simplified design compared to the state of the art and can be used efficiently for cell culture processes. It is particularly an object to provide a bioreactor which cannot be arbitrarily opened and closed in order to reduce the risk of contamination.